In recognition of increasing health differential among socioeconomic, gender, and ethnic subgroups, the Healthy People 2010 has set its second goal as elimination of health disparities in the US population. Accordingly, the FY 2004 Plans and Priorities for Cancer Research of the National Cancer Institute has also stated the goal "To understand the fundamental causes of health disparities in cancer, including the influence of social position and economic status...". Socioeconomic position related health disparities may be attributable to income, access to health care, environmental exposures, and health risk behaviors including diet. Diet has been shown to relate to three of the leading causes of death in the US (coronary heart disease, certain cancers, and stroke). However, little is known about the independent association of measures of socioeconomic position-level of education, income, poverty, and occupation--with dietary attributes within a multivariate framework. Also, there is no published information on how the association of diet and socioeconomic position may be changing over time in the US population. Therefore, the overall objectives of the proposed study are to examine: 1) the independent association of measures of socioeconomic position with self-reported diet quality and objective biomarkers of dietary intake, and 2) the trends in the association of socioeconomic position with diet quality from 1971-2000. The study will use nationally representative data from the National Health and Nutrition Examination Surveys conducted in 1971-1975 (n>10,000), 1976-1980 (n>10,000), 1988-1994 (n>l 3,000), and 1999-2000 (n>3700), to address these issues in gender, race/ethnicity specific analyses. The importance of dietary risk factors for decreasing the risk of chronic diseases is underscored by the fact that dietary risk factors are amenable to intervention, and diet is universally consumed and even a small relative risk may have a considerable public health impact. The results of this study will help in evaluating the effectiveness of past efforts at promoting desirable dietary behavior changes in high risk populations and design of newer strategies to target dietary attributes associated with socioeconomic position. The proposed study will thus contribute to progress towards the stated goals of Healthy People 2010 and the National Cancer Institute.